Packaging machines are available in which bodies of this type are individually wrapped and then sealed in wrapping elements, the wrapping element being formed in most cases by a piece of paper and in some cases by a piece of card as well.
A machine of this type is described in out British Patent Applications publication Nos. 2130544 and 2144702.
The machine described comprises a drum having a housing passing through it along a diameter, in which housing there is sufficient space for a single body of the above-mentioned type and a block. In this housing the block is frictionally mounted and can slide alternately from one end to the other along the housing. The drum rotates intermittently by a half turn about its axis and pauses after every half turn. During the pause one end of this housing faces an insertion station and the other end faces an ejection station. Wrapping elements are supplied sequentially to the insertion station in a substantially tangential position with respect to the drum and a body to be wrapped is also supplied adjacent to the said element. A reciprocating thrust element is provided at the insertion station, which pushes the body against the wrapping element during its operational stroke and then, as the drum is stationary, inserts it into the drum housing in such a way that a wrapping blank is obtained around the said body: the action which the thrust element exerts on the body to be wrapped is gradually transmitted to the wrapping element, to the block and to the body which, during the previous pause of the drum, has been partially wrapped and is still located within the housing, adjacent the ejection station.
It is evident therefore that the thrust element alone provides the drive causing the block to slide in the drum housing i.e. to slide from the end of the housing facing the insertion station to the opposite end facing the ejection station, through the body to be wrapped; in other words causing the ejection of the body which has previously been partially wrapped by introduction of the next body to be wrapped, into the housing. Consequently in the normal operation of the packaging machine it is necessary to maintain absolute regularity of supply to the insertion station, whilst provision has to be made to slide the block in the housing manually, to eject a body remaining in the drum at a transitional stage.
It is also obvious that the body to be wrapped is subjected to considerable force in order to cause the wrapping element to fold around it and in particular to displace the block and the previous partially wrapped body. The body to be wrapped can only withstand this force satisfactorily if it is sufficiently rigid and square. An oval body of the consistency of soap would be damaged if its smaller zones were to be acted upon by the thrust element and if it were also to operate the block.